Continuing its support for the venerable microcontroller-oriented Inter-IC (12C) and SMBus protocols, Texas Instruments Inc. has released three new 16-Bit Configurable I2C and SMBus I/O expanders.
The PCA9555, PCA9535, and the PCA9539 16-bit I/O expanders are designed to provide developers with more general MCU I/O expansion, saving the dedicated GPIO for other functions. The I2C slave devices also feature Nickel Palladium Gold (NiPdAu) RoHS compliant finish.
While all three devices have similar functionality, the PCA9539 is “first among equals" with an additional /RESET input. It can be used in an I2C system to initialize the expander to the default state without de-powering it. This is useful in situations where the I2C bus has a glitch which prevents proper transmission of data between the microprocessor and slave devices (such as the PCA9539).
Any incorrect data in the PCA9539 can then be eliminated through resetting it. Other slave devices without a /RESET input require their power supply to be lowered to 0V and then powered back up to Vcc for the slave device to return to its default state which can be inefficient and time consuming in the application.
All three devices will be released in QFN package optimized for space constrained applications. Currently, the PCA9555 is available in the industry standard SSOP, TSSOP, SOIC, and TVSOP packages.
The PCA9555DGVR (TVSOP) is $1.25 in quantities of 1,000. The PCA9535 is available SSOP, TSSOP, SOIC, and TVSOP packages. Pricing for the TVSOP) is set at $1.25 in quantities of 1,000. The PCA9539 is available in the industry standard SSOP, TSSOP, SOIC, and TVSOP packages. Pring for the TVSOP version is $1.38 in quantities of 1,000.
Texas Instruments, Inc.